methodhandle

问题 With the release of Java 7 came the MethodHandle, which allows a user to invoke a method as if using its underlying bytecode. In particular, the MethodHandles.Lookup class provides factory methods to create method handles to access class members: The factory methods on a Lookup object correspond to all major use cases for methods, constructors, and fields. Each method handle created by a factory method is the functional equivalent of a particular bytecode behavior. Functionally, this is more

问题 With the release of Java 7 came the MethodHandle, which allows a user to invoke a method as if using its underlying bytecode. In particular, the MethodHandles.Lookup class provides factory methods to create method handles to access class members: The factory methods on a Lookup object correspond to all major use cases for methods, constructors, and fields. Each method handle created by a factory method is the functional equivalent of a particular bytecode behavior. Functionally, this is more

问题 With the release of Java 7 came the MethodHandle, which allows a user to invoke a method as if using its underlying bytecode. In particular, the MethodHandles.Lookup class provides factory methods to create method handles to access class members: The factory methods on a Lookup object correspond to all major use cases for methods, constructors, and fields. Each method handle created by a factory method is the functional equivalent of a particular bytecode behavior. Functionally, this is more

问题 With the release of Java 7 came the MethodHandle, which allows a user to invoke a method as if using its underlying bytecode. In particular, the MethodHandles.Lookup class provides factory methods to create method handles to access class members: The factory methods on a Lookup object correspond to all major use cases for methods, constructors, and fields. Each method handle created by a factory method is the functional equivalent of a particular bytecode behavior. Functionally, this is more

问题 I want to print hi GrandFather But it seems to print hi father. And I am not understand how to diff the use between findSpecial and findVirtual I want someone can help me. Thank you class GrandFather{ void thinking(){ System.out.println("hi GrandFather"); } } class Father extends GrandFather{ void thinking(){ System.out.println("hi Father"); } } class Son extends Father{ void thinking(){ MethodType mt=MethodType.methodType(void.class); //MethodHandle mh=MethodHandles.lookup().findVirtual

问题 I try to get the maximum performance in one of my scripts, without doing a major refactor. I spotted method that creates a BiConsumer from a Field using reflection. return (c, v) -> { try { field.set(c, v); } catch (final Throwable e) { throw new RuntimeException("Could not set field: " + field, e); } }; Reflection has the reputation of being slow. So I though I could use the method handles. Lookup lookup = MethodHandles.lookup(); MethodHandle mh = lookup.unreflectSetter(field); return (c, v)

问题 I have spend whole day on this problem. My problem is how to make an MethodHandle.invokeExact invocation on an instance, whose class type is dynamically loaded at program runtime. To make problem more clear, i show my sample code below: Class<?> expClass = new MyClassLoader().load(....) //expClass is AddSample.class which is subclass of BaseTemplate BaseTemplate obj = expClass.getConstructor(...) .newInstance(...); MethodHandle myMH = MethodHandles.lookup().findVirtual(expClass, methodName,..

问题 Suppose I have simple javabean MyPerson with a name getter and setter: public class MyPerson { private String name; public String getName() { return name; } public void setName(String name) { this.name = name; } } Now I am running this main code that simply gets and sets that name field: public static void main(String[] args) throws Throwable { MethodHandles.Lookup lookup = MethodHandles.lookup(); MethodHandle getterMethodHandle = lookup.findGetter(MyPerson.class, "name", String.class);

问题 I have this code which works fine: Method getterMethod = Person.class.getDeclaredMethod("getName"); MethodHandles.Lookup lookup = MethodHandles.publicLookup(); Class<?> declaringClass = getterMethod.getDeclaringClass(); Class<?> returnType = getterMethod.getReturnType(); CallSite getterSite = LambdaMetafactory.metafactory(lookup, "apply", MethodType.methodType(Function.class), MethodType.methodType(Object.class, Object.class), lookup.findVirtual(declaringClass, getterMethod.getName(),

问题 I'm trying to replace a reflective invocation with a MethodHandle, but varargs seem to be impossible to deal with. My reflective invoker currently looks like this: public class Invoker { private final Method delegate; public Invoker(Method delegate) { this.delegate = delegate; } public Object execute(Object target, Object[] args) { return delegate.invoke(target, args); } } My current attempt at rewriting it looks like this (the interface the Invoker exposes has to stay the same): public class